Regulating-valve for dental vulcanizers



(No Model.)

. L. STUCK. REGULATING VALVE FOR DENTAL VULOANIZERS.-

No. 401,391. Patented Apr. 16, 1889.

N PUERS. MwUtMgraphor. WllWglcn. D, C.

UNITED STATES PATENT LEVI STUCK, OF HART, MICHIGAN.

SPECIFICATION forming part of Letters Patent No. 401,391, dated April16, 1889. Application filed May 1'7, 1888. Serial No. 274,228. (Nomodel.)

To aZZ whom it may concern.-

Be it known that I, LEVI STUCK, of Hart, in the county of Oceana andState of Michigan, have invented certain new and useful Improvements inRegulating-Valves for Dental Vulcanizers; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it pertains tomake and use it, reference being had to the accompanying drawing, whichforms part of this specification. 7

- My invention relates to an improvement in regulating-valves for dentalvulcanizers; and it consists in the combination of a dental vulcanizer,a cylinder which is connected thereto and which has a valveseat in itsbottom, and a blow-off pipe with a spring-actuated valve, a graduatedstem connected with the valve, and an adjustable screw cap or cover forthe cylinder, as will be more fully described here inafter.

The object of my invention is to provide a regulatingwalve for dentalvulcanizers which will open at a certain regulated pressure and begin toallow the steam to escape, so as to give notice to the operator that thevulcanizing point has been reached, and thus notify him to note the timefrom the opening until the pressure of the steam has reached the highestregulated point, and thus dispense with the necessity of keeping a closewatch upon the thermometer connected to the vulcanizer, as hasheretofore been the case.

The accompanying drawing represents a device which embodies myinvention, the cylinder being shown in section.

A represents an ordinary vulcanizer, and B the cylinder, which isscrewed into its top or at any other suitable point. Through the bottomof this cylinder is made a straight opening, so as to receive the guideE of the valve, and in the bottom of the cylinder is made a valve-seatupon which the valve 0 rests. The opening through the bottom of thesc1'ewthreaded portion of the cylinder is made straight, so as tocorrespond to the shape of the guiding portion of the valve which fitsin this opening. When the pressure of the steam becomes sufficientlygreat to raise the valve from its seat against the pressure of thespring G, placed upon the valvestem H and regulating the pressure of thevalve upon its seat, the steam escapes freely through the escape-pipe I,which extends from the bottom of the cylinder. The steam, in passingthrough the opening in the bottom of the cylinder, bears directlyagainst the whole bottom of valve, and hence the valve will immediatelyallow the steam to escapeas soon as the regulated pressure has beenreached.

The valvestem II projects through the screw-cover J of the cylinder, andis provided with a head, L, at its upper end, so as to enable the valveto be lifted from its seat by the operator whenever he so desires. Inthe valvestem are made a number of grooves, which form a graduated scalewhich represents the different pressures of steam which are to be used.The lowest groove represents the greatest pressure and the highest theleast. The screw-cap is vertically adjustable upon the cylinder inrelation to the graduations on the valve-stem, so that the valve can beset at any desired pressure. In proportion as the cap is unscrewed itrises upon. the valve-stem, and of course lessens the tension of thespring upon the valve accordingly. If one of the marks upon the stemindicates a pressure of 300, it is only necessary to move the cap untilits upper edge coincides with this mark, and. then the steam will. blowoff at this pressure.

After the plate has been placed in the vulcanizer and the cap has beenadjusted to the pressure, say, of 300, the operator can go on about hisbusiness, and need pay no further attention to the vnleanizer, for whenthe heat reaches 300 the valve will open and the steam will begin. toescape. The escape of the steam does not indicate the safety-point, butsimply serves as a notice to .the operator that the heat has reached 300and that he is to compute the time from that moment. \Vith the constantescape of steam the rise in temperature is slightly retarded, so that itwill take just about forty minutes for the heat to reach 330. Theoperator, knowing that it will take just forty minutes to reach 330, andthat forty minutes are required to complete the vulcanizing of theplate, he can go on with his work in any part of the building after thesteam once begins to blow ofl at 300 without paying any furtherattention to anything except the passage of time. At the end of fortyminutes he will find that the heat has reached 330, when the plate willbe perfectly finished.

Heretofore safety-valves have been applied to dental Vulcanizers; butthey have served no other purpose than to prevent the pressure of steamfrom reaching a dangerous or explosive point; but my invention, whilesimilar so far as a spring-actuated valve is concerned, diifers entirelyin operation and principle from these safety-valves, because my valve isnot intended as a safety-valve, but is intended to notify the operatorthat the vulcanizing-point has been reached and to note the time afterthat moment and to allow the temperature to gradually increase up to anydesired degree. Where the operator has had heretofore to keep a closewatch upon the temperature, my invention enables him to dispense withthis trouble and to simply note the time from the moment the steambegins to blow off.

By the constant and continuous increase of pressure obtained by the useof a valve constructed to operate as here shown a much finer and tougherquality of vulcanized rubber is produced than if the heat were run atonce to 330 and continued there thirty minutes. The escape of steamdecreases to a certain degree the rapid increase of heat in thevulcanizer and retards its rising accordingly, and hence the timebetween the point at which the steam begins to blow ofi and the point atwhich the vulcanizer is completed is about forty minutes. The flamewhich heats the Vulcanizer, whether gas or oil, is difficult to socontrol that the heat shall not rise too high nor sink too low in theoperation. My invention saves the operator valuable time in watching thethermometer and all possible liability of spoiling the plates beingvulcanized, as the regulating-valve controls the entire operation bygradually and continually reducing the heat and increasing the dischargeas the steam increases in pressure. 5 As soon as the forty minutes haveelapsed from the time the steam begins to blow oif the operator turnsoif the heat and the plate is finished without the slightest liabilityof being burned or injured in any manner.

Having thus described my invention, I claim- The combination, with avulcanizer, of a cylinder provided with a valve-seat and a blow-offpipe, the valve, the graduated Valvestem, a spring applied to thevalve-stem, and an adjustable cap, by means of which the pressure of thespring is regulated to correspond to the graduations on the stem,-substantially as shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

LEVI STUCK.

Witnesses:

O. A. GURNEY, J. O. RICHMOND.

